Field of the Invention
The invention relates to a system for contactless energy and data transfer according to the independent claim.
State of the Art
The applicant offers measurement devices for object detection, for example at the internet link leading to the applicant: http://www.Balluff.com, which are based on different physical principles such as, for example, inductive distance sensors, micropulse displacement transducers, magneto-inductive displacement sensors, magnetically coded displacement and angle measurement systems and, for example, opto-electronic distance sensors. The Measurement devices ultimately determine the position of a moving object with regard to a position sensor or the distance of a moving object from the position sensor.
In patent application DE 10 2010 008 495 A1, an approach for position measurement of an object is described in which a magnet allocated to the object is moved along a magnetostrictive waveguide, wherein the magnet induces a first magnetic field component in a region in the waveguide, in which furthermore a current signal is provided with a current pulse which induces a current magnetic field in the waveguide which has at least one field component in the waveguide which deviates from the field component induced by the magnet such that, in the determined region of the magnetostrictive waveguide, a wave results due to the field change during the current pulse as a consequence of the magnetostrictive effect. The wave is detected in an evaluation unit, wherein the position of the object is determined from the travel time of the wave in the waveguide. The known approach is distinguished in that the current signal begins with a targeted, predetermined current ramp-up, the temporal course of which is determined in such a way that no wave is detected and that such a current pulse is provided in connection with the current ramp-up which leads to the emergence of a detectable wave.
In patent specification DE 101 40 930 C1, a tactile sensor system is described with which an obstruction protection is implemented on bus doors. A transponder implemented as an RFID (Radio-Frequency Identification) is provided in the door, said transponder constantly transferring a sensor signal to an evaluation unit arranged in the door frame. The energy supply of the transponder arranged in the bus door is gained from an energy signal which is constantly emitted from the evaluation unit. In the case of an obstruction procedure, a safety edge arranged in the door seal is operated which is contacted with two damping coils. The two damping coils influence the emission of the sensor signal depending on the switch status of the safety edge. In the case of a closed contact of the safety edge, the sensor signal is dampened strongly or is completely suppressed. The field strength decrease or the complete elimination of the emitted sensor signal is classified as an obstruction procedure by a receiving unit in the evaluation unit.
In patent application DE 10 2011 114 612 A1, a method to process Kanban tasks and an RFID pallet box are known. To process order procedures in the scope of task processing in the supply of small parts between a supplier and a client, containers filled with small parts are supplied by the supplier to an extraction point and containers emptied by the client are given back again. The containers are equipped with RFID transponders which are able to be read in a reading procedure and which contain data concerning the containers. Several containers are arranged in a box. The reading procedure after the adjustment of an empty container in the box is triggered by a door or a cover of the box being closed.
The not previously published international application PCT/DE2013/000676 A1 describes a position measurement device having a position sensor which contains a position sensor transmitter/receiver antenna, a transmission unit, a current supply as well as a switch element. The position measurement device furthermore comprises an evaluation unit which contains an evaluation unit transmitter/receiver antenna, via which the evaluation unit emits an energy signal from which the current supply of the position sensor gains energy for the transmission unit. The evaluation unit furthermore contains a receiving unit which provides an output signal. An operating element is provided which is allocated to a moving object and which operates the switch element of the position sensor for a predetermined position of the object or from a predetermined distance of the object from the position sensor. In the case of a closed switch element, the position sensor emits a data signal via the position sensor transmitter/receiver antenna which the evaluation unit transmitter/receiver antenna receives and which provides the receiving unit with the initial signal as a measure for the position of the object. The known position measurement device provides a wireless position sensor such that an expensive cabling of the position sensor which was required previously is omitted. As a result of the position sensor of the known position measurement device only emitting the position signal in the case of a closed switch element and additionally not transmitting it in this case, the evaluation unit receives a clear signal which can be allocated correspondingly clearly to a certain position of the moving object with regard to the position sensor or a distance of the moving object from the position sensor.
Patent application U.S. 2012/126832 A1 describes a proximity sensor which contains a position sensor which transmits positional information wirelessly to an evaluation unit. The position sensor contains a microwave transmitter which emits a microwave signal which is influenced by an object located in proximity thereto. An approaching object detunes the microwave transmitter by a change of the load thereof. Transmitter/receiver antennae are not present either in the position sensor or in the evaluation unit. A wireless transfer of the energy required for the position sensor from an evaluation unit to the position sensor is not provided.
Document DE 199 23 376 A1 describes a device for wireless position detection of an object. The position sensor contains both a transmitter antenna and a receiver antenna. The transmitter antenna emits a high-frequency signal which is received by the receiver antenna, wherein the coupling is influenced by the object. The coupling between the position sensor and an evaluation unit occurs using wires.
Document DE 197 38 299 A1 describes a sensor which works wirelessly and which is used in a tool holder. A surface wave sensor is provided as a sensor, which provides a measurement signal which can be requested via a wireless connection. The energy supply of the surface wave sensor likewise occurs via the wireless connection. A switch element can be provided which activates a reflector mark which influences the signal of the surface wave sensor or which switches a transmitter/receiver antenna of the surface wave sensor on or off.
Patent application U.S. Pat. No. 5,649,295 A describes a wireless communication system in which a stationary unit communicates wirelessly with mobile units. Besides the wireless data transfer, the energy supply of the mobile units also occurs via a high-frequency connection. The communication system corresponds to an RFID system. Such an RFID system is described in detail in patent specification U.S. Pat. No. 6,107,910 A.
In the case of sensor systems which work wirelessly and in which the energy required for a mobile part is gained from an energy signal which is emitted from a base part, it must, on the one hand, be ensured that sufficient energy to operate the mobile part can be provided in the predetermined transfer region between the base part and the mobile part and that, on the other hand, specifications relating to the emission of high-frequency signals are complied with.
The object of the invention is to specify a system which works in a contactless manner for contactless energy and data transfer with an optimum wireless energy transfer from a base part to a mobile part.
The object is solved by the features specified in the independent claim.